Hawaii · zones 12a–12a
When to plant spinach in Hawaii.
Sow between Jan 1 to Jan 1 in a typical year, keyed to Hawaii's median last frost around Jan 1. A second, fall sowing fits Oct 17 to Dec 5. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Spinach dates for a typical Hawaii season.
Direct sow
Jan 1 to Jan 1
Keyed to the ~Jan 1 last frost. Sow 0.5" deep, 3" apart.
Fall round
Oct 17 to Dec 5
Counted back from the ~Dec 31 first frost.
Harvest
~42 days later
~0.25 lb per plant over ~1 weeks.
Hawaii spans more than one climate: Zone 12 is the most common zone, but the state runs 12a to 12a. That's why the planner works from your ZIP code's frost dates, not your zone — mountain and coastal gardens in the same state can be three weeks apart.